Base Class: Barbarian
Beneath the ground ebbs an eternal roil of fire and stone. As the land shapes and reshapes again beneath our feet, ignorant of our motives as we are in return to its motions, it sets of a chain of events that can lead to devastating earthquakes, volcanic eruptions, and even the formation of new mountains. Few dare to face the reality of such an unstoppable force, but those who walk the Path of the Erupting Earth not only to accept the land's destructive power, but embrace it to their own end, unleashing a roaring fire from their own hearts that allows them to call upon the fury of the earth and shatter the land.
Most barbarians who walk the Path of the Erupting Earth are usually dwarves who live deep within the earth, either in the heart of volcanoes or close to rivers of magma, though it also appeals to humans and orcs who live in similar circumstances. Some may have religious leanings to gods of fire and earth, though most are drawn to the path due to the indifferent, yet primal nature of the land rather than a spiritual connection.
Molten Fury
Starting when you choose this path at 3rd level, your rage radiates from within. While you’re raging, an aura that radiates a scorching heat that will ignite all flammable objects that aren't being worn or carried in a 10ft radius around you. Whenever anyone you perceive to be an enemy enters or starts their turn in the aura they have to make Constitution save takes 1d6 fire damage on a failed save, or half as much damage on a successful one. The damage increases when you reach certain levels in this class, increasing to 2d6 at 10th level, 3d6 at 15th level, and 4d6 at 20th level.
Your aura’s effects require a saving throw, the DC equals 8 + your proficiency bonus + your Constitution modifier.
Earthly Connection
With your connection with the land you are able to cast mold earth as a cantrip and meld to stone but only as a ritual spell
Inevitable Arrival
Beginning at 6th level, you become as unstoppable as a force of nature. You ignore the movement penalties of any difficult terrain involving rocks or stone and your speed cannot be reduced below the base movement speed(s) granted by your race. You are still affected by effects that knock you prone, petrify, grapple, paralyze, restrain, stun you, or knock you unconscious.
Shattered Earth
Starting at 10th level, you can shatter the ground beneath you and release explosive magma from the depths of the earth. As an action while raging, you may smash your weapon into the ground and release plumes of fire in an area. The area can either be a 15-foot cone or a 30-foot long, 5-foot wide line, both starting from your location. Creatures in that area must make a Dexterity saving throw equal to 8 + your proficiency modifier + your strength modifier. Those creatures take 4d8 fire damage on a failed save, or half as much of a successful one. After the attack, the affected area becomes difficult terrain.
The fire damage dealt increases to 5d8 at 14th level and 6d8 at 18th level.
After using this ability, you cannot use it again until you finish a long rest.
Eruption
Beginning at 14th level, you erupt into a volcanic fury whenever you enrage, and you gain resistance to fire damage. Whenever you enrage, all creatures within 20 feet of you must make a dexterity saving throw. The DC for this save equals (8 + your proficiency bonus + your constitution modifier). On a failed save, a creature takes 10d6 fire damage, or half as much on a success. You are immune to this damage. The fire spreads around corners and ignites all flammable objects that aren't being worn or carried, except for the ones on your person. While you are still raging, you can use an action to repeat this effect, forcing every creature to repeat the saving throw. However, you are not immune to subsequent eruptions after your initial rage, and automatically fail your saving throws against this ability.